This invention relates generally to the field of surgery and more particularly to a data display device for microsurgery.
In many types of surgery, particularly microsurgery, the surgeon operates through an operating microscope using various electronic, pneumatic or hydraulic handpieces that are controlled by a control console. Whenever the surgeon wishes to know the operative settings of the console, the surgeon must either have an assistant read the settings, or the surgeon must look up from the operating microscope and read the settings. A device that allows the surgeon to view the console operative settings within the field of view of the microscope is desirable.
Typical operating room microscopes use an objective lens system that relays the image through the body of the microscope and reforms (focuses) the inverted image on the reticle plane of the oculars. The inverted image can, at this point, can be combined with a reticle that can be calibrated to provide measurement capability or simply qualitatively define a portion of the microscopes'field of view (FOV). The ocular eyepiece lens relays the combined image (field image plus reticle) to the observer's eye, which forms the correct (erect) image on the retina. Thus, the reticle image plane is a convenient place to add additional information to the observer's FOV.
Several prior attempts to provide intraocular or "heads-up" data displays have been made. For example, U.S. Pat. No. 4,544,243 (Munnerlyn) discloses a surgical microscope data display device that uses a cathode ray tube projector coupled to a beamsplitter mounted to the microscope between the oculars and the objective lens. While this device does project data to the surgeon, it does not project data to any surgical assistant. This device also diverts a significant portion of the image intensity away from the surgeon by the nature of the beamsplitter, eliminates the opportunity for a viewing attachment, is bulky and heavy and, thus, impractical, and does not take advantage of the inherent convenience of inserting data at the reticle image plane.
Others attempts have included eliminating the oculars and positioning the surgeon and assistant in front of a television monitor. This system permits electronic insertion of data into the display image, but the resolution, contrast, dynamic range of the image and depth perception were all degraded. In addition, these types of devices forced the surgeon to operate in a position different from his/her surgical training.
Downing and others have developed a 3-D volumetric display based on 2-step, 2-frequency upconversion fluorescence in rare-earth doped glass. Two laser beams of two different wavelengths are spatially mixed within the glass volume. The wavelengths are chosen to match the upconversion process selected (a function of the rare-earth dopant of the glass). Information within the glass volume is produced by spatially and temporarily modulating one or both laser beams. Scanning systems and modulators for each laser are electronically coordinated to produce Lissajous figures within a glass cube. Fluorescence produced by this process can be viewed at any angle. In a non-illuminated state, the glass cube is essentially clear and distortion-free. Downing also envisioned a 2-D version of this display device having a 1.times.N array of laser diodes addressing N.sup.2 voxels, however, laser diodes intrinsically do not produce collimated beams in highly planar media. See U.S. Pat. No. 5,684,621 (Downing), the entire contents of which is incorporated herein by reference. The described 2-D device will have a highly uneven luminance distribution when uniformly raster-scanned because in one corner of the display, the beams have very short path lengths while in the opposite corner, the beams must travel the maximum path length. With rapidly diverging beams, the confluence of the beams traveling the maximum distance will produce very low or no fluorescence, as compared to the beams traveling the shortest path length, and also will produce non-uniform pixel size.
Therefore, a need continues to exist for an intraocular data display device that is positioned on the reticle image plane of a microscope ocular with no optical path modifications, uniform display intensity and with little or no loss in image intensity to the observer.